1. Field of the Invention
The present invention relates to a novel sulfur scavenger including a diamine terminated reaction product of a primary amine and an aldehyde under conditions to reduce or preclude triazine formation.
More particularly, the present invention relates a novel sulfur scavenger including a diamine terminated reaction product of a primary amine and an aldehyde, where at least one aldehyde is added to a solution of at least one alkylamine under conditions to reduce or preclude triazine formation to produce a sulfur scavenging composition that does not liberate aldehyde upon heating and where trace imines are chemically reduced by adding a reducing agent to the crude product prior to workup.
2. Description of the Related Art
Noxious sulfur species, such as hydrogen sulfide and thiols, are present in many industrial and waste management environments such as oil and gas production, refining, chemical processing and manufacturing, coal gasification, sewage treatment and other industrial and waste management process. Many compounds have been prepared and patented to reduce these noxious sulfur species converting them to higher molecular weight sulfur containing materials, many of which are water soluble or have a higher partition coefficient for water than hydrocarbon. Such scavengers are disclosed in U.S. Pat. Nos. 4,748,011; 4,978,512; 4,748,011; 4,978,512; 2,390,153; 3,856,921; 4,112,050; 4,112,051; and 4,112,052. Many of these compositions also have utility in converting other troublesome compounds such as carbon dioxide into more benign compounds. See “Sterically Hindered Amines for CO2 Removal from Gases” in I & EC FUNDAMENTALS, Vol. 2, No. 22 (1983).
Although many sulfur scavengers have been prepared and used in these industrial and water management applications, there is still a need in the art for compositions to reduce, reduce to a desired level or eliminate noxious sulfur agents or other troublesome compounds that are thermally stable, contain little or no triazines or other compounds that are known to liberate aldehyde upon heating and have acceptable properties for use in capillary coiled tubing applications, applicationw where small diameter tubing it inserted into a well to a given depth and chemical agents such as sulfur scavengers are injected into the well fluid through the tubing.